U.S. patent application number 11/358113 was filed with the patent office on 2006-08-24 for laser beam machine.
This patent application is currently assigned to HAMAMATSU PHOTONICS K.K.. Invention is credited to Syunichi Gonda, Hirofumi Kan, Hirofumi Miyajima, Yujin Zheng.
Application Number | 20060186095 11/358113 |
Document ID | / |
Family ID | 36776424 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060186095 |
Kind Code |
A1 |
Kan; Hirofumi ; et
al. |
August 24, 2006 |
Laser beam machine
Abstract
In this laser beam machine 1, while a pressing portion 9 of an
optical guide member 6 presses a lid 13 against a body 12 of a
container, the optical guide member 6 annularly guides a laser beam
propagated through an optical fiber 4 and outputs it from the
pressing portion 9. Thereby, an annular processing region of the
body 12 and the lid 13 is entirely irradiated with the laser beam
at one time and the lid 13 can be joined to the body 12, whereby
improving the working efficiency. Such improvement in working
efficiency shortens the processing time and improves the production
yield. Furthermore, this laser beam machine 1 does not need to be
separately provided with a rotating mechanism for laser beam
scanning and a pressurizing mechanism for the body 12 and the lid
13, so that construction of the machine can be significantly
simplified.
Inventors: |
Kan; Hirofumi;
(Hamamatsu-shi, JP) ; Gonda; Syunichi;
(Hamamatsu-shi, JP) ; Miyajima; Hirofumi;
(Hamamatsu-shi, JP) ; Zheng; Yujin;
(Hamamatsu-shi, JP) |
Correspondence
Address: |
DRINKER BIDDLE & REATH (DC)
1500 K STREET, N.W.
SUITE 1100
WASHINGTON
DC
20005-1209
US
|
Assignee: |
HAMAMATSU PHOTONICS K.K.
|
Family ID: |
36776424 |
Appl. No.: |
11/358113 |
Filed: |
February 22, 2006 |
Current U.S.
Class: |
219/121.67 |
Current CPC
Class: |
B23K 26/244 20151001;
B29C 66/542 20130101; B29C 66/71 20130101; B23K 26/0734 20130101;
B29C 65/1677 20130101; B29K 2067/003 20130101; B23K 26/037
20151001; B29C 66/21 20130101; B23K 26/28 20130101; B29C 66/71
20130101; B29C 65/1629 20130101; B29C 65/1687 20130101; B29C
65/1664 20130101; B29C 65/1667 20130101; B29C 66/1312 20130101;
B29C 66/545 20130101; B29C 66/24221 20130101 |
Class at
Publication: |
219/121.67 |
International
Class: |
B23K 26/16 20060101
B23K026/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2005 |
JP |
P2005-047846 |
Claims
1. A laser beam machine for joining a first workpiece material to a
second workpiece material by irradiating a laser beam, comprising:
an optical fiber for propagating the laser beam; and an optical
guide member that has a connecting portion to be optically
connected to the optical fiber and a pressing portion to press the
first workpiece material against the second workpiece material, and
annularly guides the laser beam from the connecting portion to the
pressing portion and outputs the laser beam from the pressing
portion.
2. The laser beam machine according to claim 1, wherein a groove
having a bottom from which the laser beam exits is annularly formed
in the pressing portion.
3. The laser beam machine according to claim 1, wherein the optical
guide member is formed into a cap shape broadened toward the
pressing portion from the connecting portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a laser beam machine for
joining a first workpiece material to a second workpiece material
by irradiating a laser beam.
[0003] 2. Related Background of the Invention
[0004] Conventionally, as a technique related to this kind of
field, for example, a laser beam welding method is described in
Japanese Published Unexamined Patent Application No. H06-106371. In
this welding method, while pressurizing with a pressurizing roll,
first and second workpiece materials (for example, a body and a lid
in canning) overlapped with each other are rotated and welded by
scanning a laser beam along the overlapping portion.
SUMMARY OF THE INVENTION
[0005] However, in the conventional welding method, it is necessary
to scan a laser beam along the overlapping portion between the
first and second workpiece materials, so that high working
efficiency cannot be obtained. In addition, a pressuring mechanism
for the first and second workpiece materials and a rotating
mechanism for scanning a laser beam are necessary, so that
construction of the welding apparatus becomes complicated.
[0006] The invention was made to solve the problems, and an object
thereof is to provide a laser beam machine which can efficiently
join a first workpiece material to a second workpiece material by a
simple construction.
[0007] To solve the problems, the laser beam machine relating to
the invention joins a first workpiece material to a second
workpiece material by irradiating a laser beam, comprising an
optical fiber for propagating the laser beam, and an optical guide
member that has a connecting portion to be optically connected to
the optical fiber and a pressing portion to press the first
workpiece material against the second workpiece material, and
annularly guides the laser beam from the connecting portion to the
pressing portion and outputs the laser beam from the pressing
portion.
[0008] In this laser beam machine, while the pressing portion of
the optical guide member presses the first workpiece material
against the second workpiece material, a laser beam propagated
through the optical fiber is annularly guided by the optical guide
member and outputted from the pressing portion. Thereby, the entire
annular processing region of the first and second workpiece
materials is irradiated with the laser beam at one time, whereby
the first workpiece material can be joined to the second workpiece
material. This improves the working efficiency. Such improvement in
working efficiency shortens the processing time and improves the
production yield. Furthermore, this laser beam machine does not
need to be separately provided with a rotating mechanism for laser
beam scanning and a pressurizing mechanism for the first and second
workpiece materials, so that construction of the machine can be
significantly simplified.
[0009] It is preferable that a groove having a bottom from which
the laser beam exits is annularly formed in the pressing portion.
Thereby, the pressing portion can be separated from the processing
region, so that the first workpiece material can be prevented from
being welded to the optical guide member when it is joined.
Thereby, the working efficiency for joining can be further
improved.
[0010] It is preferable that the optical guide member is formed
into a cap shape broaden toward the pressing portion from the
connecting portion. With such a construction of the optical guide
member, it can be easily and reliably realized that the first
workpiece material is pressed against the second workpiece material
and that a laser beam introduced from the optical fiber is
annularly guided toward the pressing portion.
[0011] The present invention will be more fully understood from the
detailed description given hereinbelow and the accompanying
drawings, which are given by way of illustration only and are not
to be considered as limiting the present invention.
[0012] Further scope of applicability of the present invention will
become apparent from the detailed description given hereinafter.
However, it should be understood that the detailed description and
specific examples, while indicating preferred embodiments of the
invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will be apparent to those skilled in the art from this
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a construction view of an embodiment of a laser
beam machine according to the invention;
[0014] FIG. 2A is a perspective view of an optical guide member,
and FIG. 2B is a longitudinal sectional view of the same;
[0015] FIG. 3 is a main part sectional view of the laser beam
machine shown in FIG. 1 in working order; and
[0016] FIG. 4A is a perspective view of a modified example of the
optical guide member, and FIG. 4B is a perspective view of another
modified example of the optical guide member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] A preferred embodiment of the laser beam machine according
to the invention is explained in detail with reference to the
drawings.
[0018] FIG. 1 is a construction view of an embodiment of a laser
beam machine constructed according to the invention. The laser beam
machine 1 shown in FIG. 1 is constructed for joining a lid to a
body of a container at a canning site. This laser beam machine 1
comprises a light source 2 that outputs a laser beam, a collimator
optical system 3 that shapes the laser beam outputted from the
light source 2, an optical fiber 4 that propagates the laser beam
shaped by the collimator optical system 3, and an optical guide
member 6 that outputs the laser beam propagated through the optical
fiber 4 to a processing region.
[0019] As the light source 2, for example, a semiconductor laser
array is used. A laser beam outputted at a predetermined power from
this light source 2 is collimated and condensed by the collimator
optical system 3, and coupled to the core of the optical fiber 4.
Then, the laser beam propagates through the optical fiber 4, and
then enters the optical guide member 6 in a circular beam pattern.
The optical fiber 4 is not limited to a single optical fiber, but
can be a bundle fiber including a plurality of optical fibers
inside.
[0020] As shown in FIG. 2A, the optical guide member 6 is an
optical component having a main body 7 made of quartz or boron
crown glass. This optical guide member 6 has a connecting portion 8
to be optically connected to the optical fiber 4 by a mechanical
contact via, for example, an optical connector, and has a pressing
portion 9 that presses the lid of the container against its body.
The optical guide member 6 is formed into a cap shape broadened
toward the pressing portion 9 from the connecting portion 8.
Herein, the optical guide member 6 has a hollow roughly headless
circular cone shape that uses the connection portion 8 as an apex
and uses the pressing portion 9 as a bottom, and has a height of
approximately 100 millimeters and a diameter equal to or less than
1 millimeter at the connecting portion 8.
[0021] As shown in FIG. 2B, in the optical guide member 6, an
annular groove 10 is formed in the pressing portion 9, and inside
the main body 7, a light guide portion 11 formed into a cap shape
broadened to the end for connection to the bottom 10a of the groove
10 from the connecting portion 8 is formed. This light guide
portion 11 is made of quartz doped with, for example, germanium,
and has a refractive index higher than that of the main body 7.
Therefore, a laser beam introduced from the optical fiber 4 via the
connecting portion 8 is annularly guided inside the optical guide
member 6 while being fully reflected inside the light guide portion
11, and annularly exits from the bottom 10a of the groove 10.
[0022] Next, a use example of this laser beam machine 1 is
explained with reference to FIG. 3. In this example, joining of a
circular lid 13 (first workpiece material) to a body 12 (second
workpiece material) of a columnar can is illustrated.
[0023] In this case, as shown in FIG. 3, first, the lid 13 is
covered on the body 12 by overlapping a flange portion 12a of the
body 12 and a flange portion 13a of the lid 13 with each other, and
the optical guide member 6 is placed on the lid 13. At this time,
due to the weight of the optical guide member 6 weighed on the
pressing portion 9, the lid 13 is uniformly pressed against the
body 12. Then, when the light source 2 is operated in this state,
an annular laser beam that exits from the bottom 10a of the groove
10 of the optical guide member 6 forms an annular welding portion
(processing region) W at the overlapping portion between the body
12 and the lid 13 positioned immediately under the groove 10. The
body 12 and the lid 13 are joined to each other due to this welding
portion W. This laser beam machine 1 can process various
containers, in addition to the illustrated can, such as plastic
bottles and bags for storing medicines in the same manner.
[0024] As described above, in the laser beam machine 1, while the
pressing portion 9 of the optical guide member 6 presses the lid 13
against the body 12 of the container, a laser beam propagated
through the optical fiber 4 is annularly guided by the optical
guide member 6 and outputted from the pressing portion 9. Thereby,
the entire annular processing region of the body 12 and the lid 13
is irradiated with the laser beam at one time and the lid 13 is
joined to the body 12, whereby improving the working efficiency.
Such improvement in working efficiency shortens the processing time
and improves the production yield. Furthermore, this laser beam
machine 1 does not need to be separately provided with a rotating
mechanism for laser beam scanning and a pressurizing mechanism for
the body 12 and the lid 13, so that construction of the machine can
be significantly simplified. The optical guide member 6 is formed
into a cap shape broadened toward the pressing portion 9 from the
connecting portion 8, so that it can be easily and reliably
realized that the lid 13 is pressed against the body 12 and a laser
beam introduced from the optical fiber 4 is annularly guided toward
the pressing portion 9.
[0025] Furthermore, in the pressing portion 9, a groove 10 having a
bottom 10a from which a laser beam exits is annularly formed. Thus,
by outputting a laser beam from the bottom 10a of the groove 10,
the pressing portion 9 can be separated from the welding portion W
as the processing region, so that the lid 13 can be prevented from
being welded to the optical guide member 6 when it is joined.
Thereby, the welding work can be smoothly performed.
[0026] The invention is not limited to the embodiment. For example,
in the embodiment described above, a laser beam propagated through
the optical fiber 4 is made incident on the optical guide member 6
in a roughly circular beam pattern. However, it is also possible
that the laser beam is propagated in a cladding mode through the
optical fiber 4 and made incident on the optical guide member 6 in
an annular beam pattern. Such a beam pattern can be obtained by
coupling a laser beam condensed by the collimator optical system 3
to the core of the optical fiber 4 at an angle greater than the NA
(numerical aperture) of the optical fiber 4. For, connecting
portion 8 between the optical fiber 4 and the optical guide member
6, without being limited to the mechanical contact via an optical
connector, fusion connection can also be employed. In terms of
simplicity of construction, the groove 10 and the light guide
portion 11 of the pressing portion 9 are not necessarily formed in
the optical guide member 6. In this case, the laser beam can be
annularly guided toward the pressing portion 9 by using the main
body 7 itself as an optical waveguide by means of full reflection
using a refractive index difference from the air.
[0027] Furthermore, as a modified example of the optical guide
member, an FOP (fiber optical plate) can also be applied. For
example, the optical guide member 20 shown in FIG. 4A has a clad 21
formed into a cap shape broadened toward the pressing portion 9
from the connecting portion 8 and a plurality (for example,
fifteen) of cores 22 that are housed inside the clad 21 and are
tapered so as to increase their thicknesses toward the pressing
portion 9 from the connecting portion 8. The front ends of the
respective cores 22 are circularly arranged on the pressing portion
9 side. In the optical guide member 23 shown in FIG. 4B, the front
ends of the respective cores 22 are also circularly arranged on the
connecting portion 8 side. Even by the optical guide members 20 and
23, the same effect as that of the optical guide member 6 shown in
FIG. 2A and FIG. 2B is obtained. In particular, when a laser beam
is outputted in an annular beam pattern from the optical fiber 4 by
using the above-described cladding mode propagation, by applying
the optical guide member 23 shown in FIG. 4B, further excellent
optical coupling can be realized. The insides of the optical guide
members 20 and 23 of the modified examples can be formed to be
hollow, or filled with a glass material with extremely low optical
transparency.
[0028] As described above, with the laser beam machine of the
invention, a second workpiece material can be efficiently joined to
a first workpiece material by a simple construction.
[0029] From the invention thus described, it will be obvious that
the invention may be varied in many ways. Such variations are not
to be regarded as a departure from the spirit and scope of the
invention, and all such modifications as would be obvious to one
skilled in the art are intended for inclusion within the scope of
following claims.
* * * * *